Any thoughts on the performance of this lens? I have an opprtunity to get one for about $100, but know nothing about the history/heritage of this lens. With a Promaster label, I imagine it was made by a true glass maker and rebadged as a Promaster.

Also I was wondering about the size of the lens. So far as I can tell, it lacks a tripod collar. Is it therefore safe to use on today's DSLR's (i.e. risk of damaging the lens mount on the body due to the length and weight?

If it is the one I am thinking of (f/8?), I have not heard too much good about it. When Goldwinger and I got together to shoot this past fall he had one. I do remember it was pretty light for the size. Hopefully he will see this post and comment.

I am not familiar with this particular lens, but a lot of the Promasters are made by Cosina and marketed under a number of brand names, including Promaster, Phoenix, and Cosina. I have a Phoenix 100-400 that I suspect is probably from the same series. I used it a lot until I got a Bigma, and my wife still uses it some. IQ is decent, but not great...a good poor man's substitute for a high-quality long zoom.

If it's the same basic lens, it's light enough that it doesn't put a lot of stress on the mount. The trade-off is that my lens is very flimsily constructed...lots of zoom creep (push-pull zoom)...still I got a lot of use out of it for the price I paid for it.